title: A birth cohort analysis of AIDS in Europe: high incidence among young persons at risk.
abstract: OBJECTIVE
  To study trends in AIDS incidence in Europe by age and year of birth.
  
  
  METHODS
  Age-period-cohort analyses were adopted to distinguish the different time factors of calendar year, age and year of birth.
  
  
  METHODS
  Non-aggregate AIDS incidence data from 12 European countries (1978-1994) were adjusted for reporting delay and expressed per unit of population (per 100000 persons or 100000 person-years). Age-specific incidence patterns (absolute level and rate of increase) were compared between 5-year birth cohorts for homo-/bisexual men, injecting drug users (IDU) and heterosexual contact cases.
  
  
  RESULTS
  Mean age at diagnosis increased strongly amongst IDU, but less so among homo-/bisexual men and heterosexual contact cases. Of a total 110646 reported cases (116311 after adjustment for reporting delay), 87167 (78.8%) were among people born in 1950-1974 [91951 (79.1%) after adjustment for reporting delay]. The relative impact on specific birth cohorts differed strongly by exposure group. Incidences at age ranges of 20-24 and 25-29 years among cohorts born in 1965 and after were about the same level (homo-/bisexual men, IDU) or higher (heterosexual contact cases) than older birth cohorts when these were in the same age range; rates of increase were less among homo-/bisexual men and IDU, but higher among heterosexuals. There were large differences between counties.
  
  
  CONCLUSIONS
  Overall, AIDS incidence among cohorts born in 1965 and after is about the same level (homo-/bisexual men, IDU) or higher (heterosexual contact cases) than older cohorts when these were in the same age range. Rates of increase of AIDS incidence curves suggest reduced HIV transmission amongst the most recent cohorts of homo-/bisexual men and IDU, but among young heterosexuals the epidemic is still expanding.
authors.affiliation: Department of Infectious Diseases Epidemiology, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Houweling
authors.forename: F F
authors.initials: FF
authors.lastname: Hamers
authors.forename: F
authors.initials: F
authors.lastname: Termorshuizen
authors.forename: O N
authors.initials: ON
authors.lastname: Gill
authors.forename: J C
authors.initials: JC
authors.lastname: Jager
authors.forename: R A
authors.initials: RA
authors.lastname: Coutinho
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D000328:Adult; D000367:Age Factors; D001727:Bisexuality; D015331:Cohort Studies; D018562:Disease Transmission, Infectious; D005060:Europe / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D011247:Pregnancy; D011634:Public Health; D012306:Risk; D012725:Sexual Behavior; D015819:Substance Abuse, Intravenous